Change - prefab standard parameters - yrange -
if a single token is specified (any value), it dictates a fixed minimum and automatic maximim.
Previously this was only supported when yrange=0. Caution: the behavior is now slightly
different: the fixed minima is overridden by encountered data that are less than it.

Caution - prefabs now have the new superscripts/subscripts capability enabled by default.
This can be turned off if desired.
Existing prefab applications that have pairs of '^' or '`' characters in titles or labels may be affected.

Caution - prefabs now have the new data field name encoding feature enabled by default.
This can be turned off if desired.
Existing prefab applications that display data field names (eg. in legends) and have '_' or '|' characters in data
field names may be affected.

standard parameters now include ptselect parameters
for selecting different sets of rows for different lines / bar sets / data point sets.
Other new standard parameters include xnearest and ynearest
for more control over axis min and max, echodata, and new legend-related parameters.

New prefab: processdata which allows ploticus to be used as a data processing
filter (no plots).